The present invention pertains to improvements in flexible, high tensile strength steel cables which are used, inter alia, for securing, lifting, towing or pulling objects at conditions under which a cable must withstand a heavy physical load. More specifically, the present invention pertains to flexible, high tensile strength steel cables having a protective outer covering thereon and to methods of producing such cables.
Cables made of stranded steel wire are relied upon in many commercial and industrial applications for securing, towing or lifting of heavy objects, or for otherwise repeatedly or continuously applying motive force to an object where extreme reliability of force transfer is essential, e.g. cables required for moving aircraft control surfaces, and for brakes, wenching, lifting and towing.
Steel cables are extensively used for the aforementioned purposes, and although no satisfactory substitute for such cables has yet been devised, they nonetheless have certain disadvantages and objectionable characteristics. Individual wires or strands of the cable can flare outward when the cable is cut, thus creating a hazard to workmen. Furthermore, since the cable is made of steel which is relatively hard and tough, it has a tendency to slip across the surface of an object around which it is wrapped, or from which the object is slung, such as a capstan or a heavy object to be lifted or towed. Contrariwise, if the object being secured or pulled by the cable is made of a softer material, the cable tends to scuff or scrape the surface of the object, and hence mars its surface.
Another problem that is encountered is that the wires in the strands of the cable become worn and eventually break as a result of the cable repeatedly rubbing against itself or, more seriously, being dragged over sharp or abrasive objects. In an attempt to protect the cable, not only against cutting and abrasion of the wires but also from corrosion, it must be periodically coated with grease or a heavy oil. This provides protection which is frequently inadequate, and which at best is only temporary, not to mention the difficulty of handling and the mess that it causes.
The primary object of the present invention is, therefore, to provide a flexible, high tensile strength cable comprising an improvement whereby the previously mentioned disadvantages and objectionable features are either eliminated or alleviated.
Another object is to provide a flexible, high tensile strength steel cable having a flexible, continuous coating of a vulcanized rubber thereon.
Still another object is to provide a flexible, high tensile strength steel cable having a reduced tendency to slip on surfaces of an object around which the cable is wrapped, and which is less inclined to blemish the surfaces.
Yet another object is to provide a flexible, high tensile strength steel cable having a coating thereon whereby contact of the wires of the cable against one another and with sharp or abrasive objects is prevented.
Even another object is to provide a flexible, high tensile strength steel cable with a coating thereon which protects the wires of the cable from rust and corrosion.
Another object is to provide a flexible, high tensile strength steel cable with a coating thereon which prevents flare of the wires of the strands when the cable is cut.
Still another object is to provide a process for producing a flexible, high tensile strength, steel cable having a protective coating of vulcanized rubber thereon.
Other objects and advantages of the present invention will become apparent from the following description and the appended claims.